Question

Given the following sequence, find the 50th term:

1.2, 1.4, 1.6, 1.8, 2, . . .

A. 9.8
B. 11
C. 10.8
D. 10.2

Answer 1

B. 11

Explanation:

The formula for an arithmetic sequence is

an = a1+d(n-1)

a1 =1.2 (it is the first term)

We can find the common difference by taking the second term and subtracting the first term

1.4-1.2 =.2

d=.2

n = the term number we are looking for

an = 1.2 + .2(n-1)

We are looking for the 50th term so n=50

a50 = 1.2 +.2(50-1)

= 1.2 +.2(49)

= 1.2+9.8

=11